1. Field of the Invention
The present disclosure relates generally to a multi-bin CABAC decoder, and more specifically to a 2 decision bin CABAC decoder with a shortened critical path to improve timing.
2. Description of the Prior Art
The Context-adaptive Binary Arithmetic Coding (CABAC) decoding algorithm is basically sequential computations to calculate range, offset, and lookup tables for context variables. The data dependence of CABAC decoding makes it difficult to achieve high decoding throughput resulting in the CABAC decoding complexity required to process high definition images in real time to be about 3 giga-operations per second. Basically, a CABAC decoder includes a decision bin decoder and a bypass bin decoder. By experiment, 80%-90% of all bins are encoded as decision bins, and the remaining bins are encoded as bypass bins. Unlike other video coding tools in H.264/AVC, although it has been done as disclosed in U.S. Pat. No. 7,262,722 issued to Jahanghir et al. and included herein in its entirety by reference, it is difficult to enhance the CABAC decoding using a parallel architecture to improve the performance. Therefore, due to the sequential order decoding, the CABAC decoding becomes a major bottleneck in H.264/AVC.